Heretofore, there is known a technique for measuring and adjusting wheel alignment of automobiles from Japanese patent No. 2938984. In the patent, wheel alignment is measured on a wheel mount, with no wheel installed thereon, on an assembly line for assembling automobile bodies, for thereby increasing productivity.
According to the technique of the type described above, on an assembly line for assembling automobile bodies, after a steering device and suspensions have been installed on an automobile body that is carried by a hanger, the automobile body is removed from the hanger, and is vertically movably supported by wheel mounts that have been installed on the automobile body by the installed suspensions. Then, connectors such as chains or the like of a lowering means for lowering the automobile body are connected to front and rear portions of the automobile body, and operated to lower the automobile body to impart a predetermined load to the automobile body. The suspensions are now given a biasing force corresponding to the predetermined load under a reactive force from the wheel mounts, thus fixing the automobile body in a state closest to a running state when the automobile is completed with wheels mounted on respective axles. While the automobile is maintained in the above state, wheel alignment is measured on the wheel mounts, and then adjusted based on the measured results.
According to the above conventional process, however, since a state closest to the running state needs to be reproduced for the automobile body, it is necessary to pull the automobile body removed from the hanger downwardly with the lowering means before wheel alignment is measured and adjusted. Therefore, the conventional process is disadvantageous in that it is inefficient as relatively many man-hours are involved in measuring and adjusting wheel alignment.
When the automobile body is pulled downwardly by the lowering means, it may be difficult to apply the load uniformly to the four wheel mounts depending on the positions where the chains or the like of the lowering means are connected, resulting in a reduction in the accuracy with which to measure wheel alignment and a failure to adjust wheel alignment accurately.